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Monitoring the Health Care Safety Net

Slide Presentation by Andrew W. Bazemore, M.D.

On September 25, 2003, Andrew W. Bazemore, M.D. made a presentation in the Web-Assisted Audioconference entitled Mapping Tools for Monitoring the Safety Net.

This is the text version of Mr. Bazemore's slide presentation. Select to access the PowerPoint® slides (1.1 MB).

Mapping Tools for Monitoring the Safety Net

Andrew W. Bazemore, M.D.
Institute for Health Policy and Health Services Research
University of Cincinnati

Slide 1

What is a Geographic Information System (GIS)?

  • Software capable of linking geographically-referenced data together with graphic map features
    • Eases comprehension of complex data
    • Allows multiple data layers to be viewed simultaneously, or dynamically
    • Permits map production, analysis, and modeling

Slide 2

Analytic Mapping and CHCs: Possibilities

  • Define CHC Health Service Areas
  • Examine CHC "market" penetration rates
  • Find underserved areas within MUA service areas
  • Determine areas of inequitable access to subgroup populations in need of services
  • Improve capacity for COPC by each network
  • Create Web-based Interactive mapping at clinic level

Slide 3

GIS & CHC's: Utilization & Access

This slide contains two maps. These maps depict Boone County Missouri, with the black boundary lines representing the borders of U.S. census tracts. Columbia, a medium-sized city, is in the center of the county.

The map on the left shows census tracts (in white) that were federally designated as Medically Underserved Areas. These are areas to be targeted by Community Health Centers applying for federal funding. Using actual patient visit data from Boone County's two federally-funded CHC's, the map on the right was created, showing (in white) the actual census tracts that make up these 2 CHC's service area—the tracts that most of their patients come from.

The two maps, the left showing an 'Ideal Service Area' for the clinics and the right showing an 'Actual Service Area' for the clinics, don't match.

Instead of deciding that this discrepancy represented service failure, the Boone County CHC's used these maps as evidence in the successful pursuit of expansion grants to outlying portions of the county.

Slide 4

This slide contains a map. Analytic mapping techniques were next tested in a large urban setting, working with the largest network of CHC's in Baltimore, MD. This composite map depicts the census tracts falling into each of four clinics' health service areas—depicted individually in green, blue, red, and yellow. Brown and Pink-shaded census tracts depict census tracts which fall into more than one clinic's health service area. This map was helpful to administrators, who had not previously recognized the overlap in health service areas among three of their clinics. The directors of one clinic depicted were under scrutiny of one of the network's directors, as they were thought to be losing patients to competitors. This map and a series of more specific subpopulation maps helped to demonstrate that the patients lost by this clinic were actually being lost to two of its 'sister' clinics in the network.

Slide 5

MUA Census Tracts for a Baltimore CHC

Similar to the map of Boone County Missouri, this map depicts the federally-designated Medically Underserved Area Census tracts (IN PINK) targeted for service by one of the Baltimore CHC's with whom we worked. The bullseye pattern overlay shows concentric circles at quarter mile intervals moving outward from the clinic. The blue circles are at 1 and 2 miles out from the clinic respectively.

We were asked early in the mapping process to evaluate a pending decision by clinic leaders in Baltimore to move one of their clinics two miles to the northeast of its current location in order to save money on a lease. That move would have put the new clinic on the outermost blue circle at the upper righthand portion of the map. You can see that this new location would still fall well within the targeted Medically Underserved Census Tracts (the pink area).

Slide 6

This slide contains a map. Bazemore mapped all users of this clinic in the past 12 months (RED & GREEN dots), as well as the health service area and specific patient subgroups that would be vulnerable to service loss if the clinic were moved (MAPS NOT SHOWN HERE). It became obvious that a large cluster of their patients resided to the South and East of the clinic (BOTTOM & LEFT of this map). Many of these were patients thought to be particularly vulnerable if the clinic were moved. As a result of the maps, the scheduled move was cancelled.

Slide 7


  • Definition of 'Ideal Service Area'
  • Urban setting = Multiple Providers
  • Technology-driven: Expense/Training

Slide 8

CHC Response to Mapping

  • Focus Groups/Key Informant Interviews
  • Responses and Suggestions
    • Uniformly positive responses
    • Great tool for strategic planning/resource allocation
    • Maps easily comprehended by clinic leaders
    • Correlation w/knowledge of community needed
    • Dynamic maps superior to static maps
  • Many future mapping projects proposed

Slide 9


GIS: a flexible and powerful tool to:

  • Assess patterns of CHC service
  • Engage CHC leaders and communities
  • Aid in strategic planning and resource allocation

Current as of February 2004

Internet Citation:

Mapping Tools for Monitoring the Safety Net. Text Version of a Slide Presentation at a Web-assisted Audioconference. Agency for Healthcare Research and Quality, Rockville, MD.

Return to Audioconference

The information on this page is archived and provided for reference purposes only.

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